Tweaked syntax to avoid compilation error

[vlaze]

This little fix prevents a compilation error under GNU/Linux systems which says:

In file included from call.c:38:0:
dynasm/dasm_x86.h: In function ‘dasm_put’:
dynasm/dasm_x86.h:207:2: error: this ‘if’ clause does not guard... [-Werror=misleading-indentation]
  if (*p++ == 1 && *p == DASM_DISP) mrm = n; continue;

Copying the syntax of other lines of code, the problem seems to be fixed. Found in an Arch Linux machine using Lua 5.3.3.