kexec: check size before trying the malloc

If size is zero, it is unnecessary to do the malloc operation.
So checking size first is better than doing malloc first.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 1 insertions, 1 deletions

diff --git a/kexec/kexec.c b/kexec/kexec.c
index 3ef6f0d4..494c5b3f 100644
--- a/kexec/kexec.c
+++ b/kexec/kexec.c
@@ -76,9 +76,9 @@ static char *xstrdup(const char *str)
 void *xmalloc(size_t size)
 {
 	void *buf;
-	buf = malloc(size);
 	if (!size)
 		return NULL;
+	buf = malloc(size);
 	if (!buf) {
 		die("Cannot malloc %ld bytes: %s\n",
 			size + 0UL, strerror(errno));