Fix clang compiler warnings on FreeBSD in erts

The following are deliberately left, as I have only a list of compiler
warnings and no system to test on:
hipe/hipe_x86_signal.c:264:5: warning: no previous prototype for function '_sigaction' [-Wmissing-prototypes]
int __SIGACTION(int signum, const struct sigaction *act, struct sigaction *oldact)
    ^
hipe/hipe_x86_signal.c:222:21: note: expanded from macro '__SIGACTION'
                    ^
1 warning generated.
sys/unix/sys_float.c:835:16: warning: declaration of 'struct exception' will not be visible outside of this function [-Wvisibility]
matherr(struct exception *exc)
               ^
sys/unix/sys_float.c:835:1: warning: no previous prototype for function 'matherr' [-Wmissing-prototypes]
matherr(struct exception *exc)
^
2 warnings generated.
drivers/unix/unix_efile.c:1504:11: warning: implicit declaration of function 'sendfile' [-Wimplicit-function-declaration]
        retval = sendfile(in_fd, out_fd, *offset, SENDFILE_CHUNK_SIZE,
                 ^
1 warning generated.

1 files changed, 2 insertions, 4 deletions

diff --git a/erts/emulator/beam/packet_parser.c b/erts/emulator/beam/packet_parser.c
index f1cfa8df39..1e301e3593 100644
--- a/erts/emulator/beam/packet_parser.c
+++ b/erts/emulator/beam/packet_parser.c
@@ -460,11 +460,9 @@ int packet_get_length(enum PacketParseType htype,
         hp = (struct tpkt_head*) ptr;
         if (hp->vrsn == TPKT_VRSN) {
             plen = get_int16(hp->packet_length) - hlen;
-            if (plen < 0)
-                goto error;
-        }
-        else
+        } else {
             goto error;
+	}
         goto remain;
     }