media: staging: atomisp: sh_css_calloc shall return a pointer to the allocated space

The calloc function returns either a null pointer or a pointer to the
allocated space. Add the second case that is missed.

Fixes: da22013f7df4 ("atomisp: remove indirection from sh_css_malloc")
Signed-off-by: Sergei A. Trusov <sergei.a.trusov@ya.ru>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/staging/media/atomisp/pci/atomisp2/css2400/sh_css.c

@@ -1939,6 +1939,7 @@ void *sh_css_calloc(size_t N, size_t size)
 		p = sh_css_malloc(N*size);
 		if (p)
 			memset(p, 0, size);
+		return p;
 	}
 	return NULL;
 }