lib/test_bitmap.c: fix bitmap optimisation tests to report errors correctly

I had neglected to increment the error counter when the tests failed,
which made the tests noisy when they fail, but not actually return an
error code.

Link: http://lkml.kernel.org/r/20180509114328.9887-1-mpe@ellerman.id.au
Fixes: 3cc78125 ("lib/test_bitmap.c: add optimisation tests")
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@vger.kernel.org>	[4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_bitmap.c

@@ -331,23 +331,32 @@ static void noinline __init test_mem_optimisations(void)
 	unsigned int start, nbits;
 
 	for (start = 0; start < 1024; start += 8) {
-		memset(bmap1, 0x5a, sizeof(bmap1));
-		memset(bmap2, 0x5a, sizeof(bmap2));
 		for (nbits = 0; nbits < 1024 - start; nbits += 8) {
+			memset(bmap1, 0x5a, sizeof(bmap1));
+			memset(bmap2, 0x5a, sizeof(bmap2));
+
 			bitmap_set(bmap1, start, nbits);
 			__bitmap_set(bmap2, start, nbits);
-			if (!bitmap_equal(bmap1, bmap2, 1024))
+			if (!bitmap_equal(bmap1, bmap2, 1024)) {
 				printk("set not equal %d %d\n", start, nbits);
-			if (!__bitmap_equal(bmap1, bmap2, 1024))
+				failed_tests++;
+			}
+			if (!__bitmap_equal(bmap1, bmap2, 1024)) {
 				printk("set not __equal %d %d\n", start, nbits);
+				failed_tests++;
+			}
 
 			bitmap_clear(bmap1, start, nbits);
 			__bitmap_clear(bmap2, start, nbits);
-			if (!bitmap_equal(bmap1, bmap2, 1024))
+			if (!bitmap_equal(bmap1, bmap2, 1024)) {
 				printk("clear not equal %d %d\n", start, nbits);
-			if (!__bitmap_equal(bmap1, bmap2, 1024))
+				failed_tests++;
+			}
+			if (!__bitmap_equal(bmap1, bmap2, 1024)) {
 				printk("clear not __equal %d %d\n", start,
 									nbits);
+				failed_tests++;
+			}
 		}
 	}
 }