fix parsing insert_buffer_and_adaptive_hash_index for MySQL 5.5

Closes munin trac ticket #1355.

plugins/node.d/mysql_.in

@@ -1214,12 +1214,23 @@ sub parse_file_io {
 sub parse_insert_buffer_and_adaptive_hash_index {
     parse_section(
 	sub {
+	    # MySQL < 5.5
 	    m/\G(\d+) inserts, (\d+) merged recs, (\d+) merges\n/gc && do {
 		$data->{ib_ibuf_inserts}    = $1;
 		$data->{ib_ibuf_merged_rec} = $2;
 		$data->{ib_ibuf_merges}     = $3;
 		return 1;
 	    };
+	    # MySQL >= 5.5
+	    m/\Gmerged operations:\n insert (\d+), delete mark \d+, delete \d+\ndiscarded operations:\n insert (\d+), delete mark \d+, delete \d+\n/gc && do {
+		$data->{ib_ibuf_inserts} = $1;
+		$data->{ib_ibuf_merged_rec} = $1 + $2;
+		return 1;
+	    };
+	    m/\GIbuf: size \d+, free list len \d+, seg size \d+, (\d+) merges\n/gc && do {
+		$data->{ib_ibuf_merges} = $1;
+		return 1;
+	    };
 	}
     );
 }