Fix for #3255

We don't have to generate a temp name ourselves, it'll be done in apr_global_mutex_create().
We don't have to provide a filename, apr_global_mutex_create() generates one automatically.
Moreover, under Unix & Windows, the preferred mechanism won't use a file at all.
apr_file_mktemp() cannot be used as it creates the file (at least on FreeBSD).
Discussion in Apache mailing list: https://lists.apache.org/thread/ykb26kg4lgcqnldvxwd9p6hv16fy4z9l

Author: Marc Stern

apache2/modsecurity.h

@@ -135,8 +135,6 @@ typedef struct msc_parm msc_parm;
 
 #define FATAL_ERROR "ModSecurity: Fatal error (memory allocation or unexpected internal error)!"
 
-#define GLOBAL_LOCK_TEMPLATE "/modsec-lock-tmp.XXXXXX"
-
 extern DSOLOCAL char *new_server_signature;
 extern DSOLOCAL char *real_server_signature;
 extern DSOLOCAL char *chroot_dir;
@@ -707,6 +705,8 @@ struct msc_parm {
 
 /* Reusable functions */
 int acquire_global_lock(apr_global_mutex_t **lock, apr_pool_t *mp);
+int msr_global_mutex_lock(modsec_rec* msr, apr_global_mutex_t* lock, const char* fct);
+int msr_global_mutex_unlock(modsec_rec* msr, apr_global_mutex_t* lock, const char* fct);
 
 /* Engine functions */