clang compiler warnings: Fix autological comparisons

This fixes autological comparison warnings in the following:
 * chan_skinny: letohl may return a signed or unsigned value, depending on the
   macro chosen
 * func_curl: Provide a specific cast to CURLoption to prevent mismatch
 * cel: Fix enum comparisons where the enum can never be negative
 * enum: Fix comparison of return result of dn_expand, which returns a signed
   int value
 * event: Fix enum comparisons where the enum can never be negative
 * indications: tone_data.freq1 and freq2 are unsigned, and hence can never be
   negative
 * presencestate: Use the actual enum value for INVALID state
 * security_events: Fix enum comparisons where the enum can never be negative
 * udptl: Don't bother to check if the return value from encode_length is less
   than 0, as it returns an unsigned int
 * translate: Since the parameters are unsigned int, don't bother checking
   to see if they are negative. The cast to unsigned int would already blow
   past the matrix bounds.
 * res_pjsip_exten_state: Use a temporary value to cache the return of
   ast_hint_presence_state
 * res_stasis_playback: Fix enum comparisons where the enum can never be
   negative
 * res_stasis_recording: Add an enum value for the case where the recording
   operation is in error; fix enum comparisons
 * resource_bridges: Use enum value as opposed to -1
 * resource_channels: Use enum value as opposed to -1

Review: https://reviewboard.asterisk.org/r/4533
ASTERISK-24917
Reported by: dkdegroot
patches:
  rb4533.patch submitted by dkdegroot (License 6600)
........

Merged revisions 434469 from http://svn.asterisk.org/svn/asterisk/branches/11
........

Merged revisions 434470 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@434471 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 3 insertions, 6 deletions

diff --git a/main/udptl.c b/main/udptl.c
index 91458489d..4e878195c 100644
--- a/main/udptl.c
+++ b/main/udptl.c
@@ -362,8 +362,7 @@ static int encode_open_type(const struct ast_udptl *udptl, uint8_t *buf, unsigne
 	}
 	/* Encode the open type */
 	for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
-		if ((enclen = encode_length(buf, len, num_octets)) < 0)
-			return -1;
+		enclen = encode_length(buf, len, num_octets);
 		if (enclen + *len > buflen) {
 			ast_log(LOG_ERROR, "UDPTL (%s): Buffer overflow detected (%u + %u > %u)\n",
 				LOG_TAG(udptl), enclen, *len, buflen);
@@ -646,8 +645,7 @@ static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, unsigned int bu
 		buf[len++] = 0x00;
 		/* The number of entries will always be zero, so it is pointless allowing
 		   for the fragmented case here. */
-		if (encode_length(buf, &len, 0) < 0)
-			return -1;
+		encode_length(buf, &len, 0);
 		break;
 	case UDPTL_ERROR_CORRECTION_REDUNDANCY:
 		/* Encode the error recovery type */
@@ -658,8 +656,7 @@ static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, unsigned int bu
 			entries = s->tx_seq_no;
 		/* The number of entries will always be small, so it is pointless allowing
 		   for the fragmented case here. */
-		if (encode_length(buf, &len, entries) < 0)
-			return -1;
+		encode_length(buf, &len, entries);
 		/* Encode the elements */
 		for (i = 0; i < entries; i++) {
 			j = (entry - i - 1) & UDPTL_BUF_MASK;