ARM: dma-mapping: Fix potential memory leak in atomic_pool_init()

When either of __alloc_from_contiguous or __alloc_remap_buffer fails
to provide a valid pointer, allocated memory is freed up and an error
is returned. 'pages' was however not freed before returning error.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

arch/arm/mm/dma-mapping.c

@@ -346,6 +346,8 @@ static int __init atomic_pool_init(void)
 		       (unsigned)pool->size / 1024);
 		return 0;
 	}
+
+	kfree(pages);
 no_pages:
 	kfree(bitmap);
 no_bitmap: