kexec: prevent double free on image allocation failure

If kimage_normal_alloc() fails to initialize an allocated kimage, it will
free the image but would still set 'rimage', as a result kexec_load will
try to free it again.

This would explode as part of the freeing process is accessing internal
members which point to uninitialized memory.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/kexec.c

@@ -242,8 +242,6 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 	if (result)
 		goto out;
 
-	*rimage = image;
-
 	/*
 	 * Find a location for the control code buffer, and add it
 	 * the vector of segments so that it's pages will also be