Merge pull request #14705 from xambroz/ruby_format_strings

Ruby format strings

src/ruby/ext/grpc/extconf.rb

@@ -94,7 +94,6 @@ $CFLAGS << ' -std=c99 '
 $CFLAGS << ' -Wall '
 $CFLAGS << ' -Wextra '
 $CFLAGS << ' -pedantic '
-$CFLAGS << ' -Wno-format '
 
 output = File.join('grpc', 'grpc_c')
 puts 'Generating Makefile for ' + output

src/ruby/ext/grpc/rb_compression_options.c

@@ -186,7 +186,7 @@ void grpc_rb_compression_options_algorithm_name_to_value_internal(
     error_message_ruby_str =
         rb_str_new(error_message_str, strlen(error_message_str));
     gpr_free(error_message_str);
-    rb_raise(rb_eNameError, StringValueCStr(error_message_ruby_str));
+    rb_raise(rb_eNameError, "%s", StringValueCStr(error_message_ruby_str));
   }
 
   grpc_slice_unref(name_slice);