Fix tests: some build hosts have ramdisk in /run/shm instead of /dev/shm

storage/rocksdb/mysql-test/rocksdb/include/have_direct_io.inc

@@ -8,7 +8,8 @@ use Cwd 'abs_path';
 
 open(FILE, ">", "$ENV{MYSQL_TMP_DIR}/data_in_shm.inc") or die;
 my $real_path= abs_path($ENV{'MYSQLTEST_VARDIR'});
-my $in_shm= index($real_path, "/dev/shm") != -1;
+my $in_shm= (index($real_path, "/dev/shm") != -1) ||
+            (index($real_path, "/run/shm") != -1);
 print FILE "let \$DATA_IN_SHM= $in_shm;\n";
 close FILE;
 EOF
@@ -18,5 +19,5 @@ EOF
 
 if ($DATA_IN_SHM)
 {
-  --skip DATADIR is in /dev/shm, possibly due to --mem
+  --skip DATADIR is in /{dev|run}/shm, possibly due to --mem
 }