mm, CMA: clean-up CMA allocation error path

We can remove one call sites for clear_cma_bitmap() if we first call it
before checking error number.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Michal Nazarewicz <mina86@mina86.com>
Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Gleb Natapov <gleb@kernel.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/cma.c

@@ -285,11 +285,12 @@ struct page *cma_alloc(struct cma *cma, int count, unsigned int align)
 		if (ret == 0) {
 			page = pfn_to_page(pfn);
 			break;
-		} else if (ret != -EBUSY) {
-			cma_clear_bitmap(cma, pfn, count);
-			break;
 		}
+
 		cma_clear_bitmap(cma, pfn, count);
+		if (ret != -EBUSY)
+			break;
+
 		pr_debug("%s(): memory range at %p is busy, retrying\n",
 			 __func__, pfn_to_page(pfn));
 		/* try again with a bit different memory target */