Fix whitespace

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/common.h b/library/common.h
index 9dbe21b..943f84c 100644
--- a/library/common.h
+++ b/library/common.h
@@ -89,10 +89,10 @@
 inline void mbedtls_xor( unsigned char *r, unsigned char const *a, unsigned char const *b, size_t n )
 {
     size_t i;
-    for ( i = 0; (i + 4) < n; i+= 4 )
+    for ( i = 0; ( i + 4 ) < n; i+= 4 )
     {
-        uint32_t x = mbedtls_get_unaligned_uint32(a + i) ^ mbedtls_get_unaligned_uint32(b + i);
-        mbedtls_put_unaligned_uint32(r + i, x);
+        uint32_t x = mbedtls_get_unaligned_uint32( a + i ) ^ mbedtls_get_unaligned_uint32( b + i );
+        mbedtls_put_unaligned_uint32( r + i, x );
     }
     for ( ; i < n; i++ )
     {