process.c: [DOC] fix grammar

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63158 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

process.c

@@ -7985,7 +7985,7 @@ InitVM_process(void)
 #if defined(HAVE_TIMES) || defined(_WIN32)
     /* Placeholder for rusage */
     rb_cProcessTms = rb_struct_define_under(rb_mProcess, "Tms", "utime", "stime", "cutime", "cstime", NULL);
-    /* An obsolete name of Process::Tms for the backward compatibility */
+    /* An obsolete name of Process::Tms for backward compatibility */
     rb_define_const(rb_cStruct, "Tms", rb_cProcessTms);
     rb_deprecate_constant(rb_cStruct, "Tms");
 #endif