x86/lib: Fix spelling, put space between a numeral and its units

As suggested by Peter Anvin.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: H . Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 1c273be..56313a3 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -98,7 +98,7 @@
 	subq $0x20,	%rdx
 	/*
 	 * At most 3 ALU operations in one cycle,
-	 * so append NOPS in the same 16bytes trunk.
+	 * so append NOPS in the same 16 bytes trunk.
 	 */
 	.p2align 4
 .Lcopy_backward_loop: