fix(bl1): prevent null pointer dereference

Added an assertion to ensure ptr is not NULL before
dereferencing it. This prevents potential null pointer
dereference issues detected by Coverity.

Change-Id: I2e3325cd7cbdf141959bacd6135461be24ae6169
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/bl1/bl1_fwu.c b/bl1/bl1_fwu.c
index 6d4dc7e..167a22e 100644
--- a/bl1/bl1_fwu.c
+++ b/bl1/bl1_fwu.c
@@ -170,6 +170,9 @@
 	uintptr_t checked_image_base, checked_image_end;
 
 	checked_desc = bl1_plat_get_image_desc(image_id);
+
+	assert(checked_desc != NULL);
+
 	checked_info = &checked_desc->image_info;
 
 	/* Image being checked mustn't be empty. */