more -Wall warning fixes from Cristian Ionescu-Idbohrn.

This time it resulted in small code changes:

function                                             old     new   delta
nexpr                                                820     828      +8
tail_main                                           1200    1202      +2
wrapf                                                166     167      +1
parse_mount_options                                  227     209     -18
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/1 up/down: 11/-18)             Total: -7 bytes

1 files changed, 2 insertions, 2 deletions

diff --git a/libbb/read.c b/libbb/read.c
index 288358d79..fb903c18a 100644
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -111,7 +111,7 @@ void xread(int fd, void *buf, size_t count)
 {
         if (count) {
                 ssize_t size = full_read(fd, buf, count);
-                if (size != count)
+                if ((size_t)size != count)
                         bb_error_msg_and_die("short read");
         }
 }
@@ -160,7 +160,7 @@ char *xmalloc_reads(int fd, char *buf, size_t *maxsz_p)
 
         goto jump_in;
         while (sz < maxsz) {
-                if (p - buf == sz) {
+                if ((size_t)(p - buf) == sz) {
  jump_in:
                         buf = xrealloc(buf, sz + 128);
                         p = buf + sz;