Fix minor issues raised in PR review

1. Style issues fixes - remove redundant spacing.
2. Remove depency of `MBEDTLS_RSA_C` in `pk_parse_public_keyfile_rsa()`
tests, as the function itself is dependent on it.
diff --git a/library/pkparse.c b/library/pkparse.c
index 41eeadf..cccc0b5 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -1325,16 +1325,16 @@
     if( ( ret = mbedtls_pk_setup( ctx, pk_info ) ) != 0 )
         return( ret );
 
-    p =  (unsigned char *) key;
+    p = (unsigned char *)key;
     ret = pk_get_rsapubkey( &p, p + keylen, mbedtls_pk_rsa( *ctx ) );
-    if ( ret == 0 )
+    if( ret == 0 )
     {
         return( ret );
     }
     mbedtls_pk_free( ctx );
-    if ( ret != ( MBEDTLS_ERR_PK_INVALID_PUBKEY + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
+    if( ret != ( MBEDTLS_ERR_PK_INVALID_PUBKEY + MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) )
     {
-        return ( ret );
+        return( ret );
     }
 #endif /* MBEDTLS_RSA_C */
     p = (unsigned char *) key;