Enhance disassembler output clarity for DROP/PASS opcodes

Modified disassembler to improve the readability of output related to
DROP and PASS opcodes.

Test: TH
Change-Id: Ice54cc218c6deef61aef0785a12c7f1ee2827207
diff --git a/disassembler.c b/disassembler.c
index 65b90d1..de6129c 100644
--- a/disassembler.c
+++ b/disassembler.c
@@ -138,7 +138,7 @@
                 print_opcode("drop");
             }
             if (imm > 0) {
-                bprintf(" %d", imm);
+                bprintf("counter=%d", imm);
             }
             break;
         case LDB_OPCODE: