mpg321: Do not unlock unititialized main_lock

Do not call sem_post() on an unitialized semaphore.

Problem spotted by <maya>.

Should fix PR pkg/53369 by <sevan>.

Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/audio/mpg321/Makefile,v
retrieving revision 1.19
diff -u -p -r1.19 Makefile
--- Makefile	2 Jun 2016 09:18:19 -0000	1.19
+++ Makefile	16 Jun 2018 10:34:29 -0000
@@ -2,6 +2,7 @@
 
 DISTNAME=	mpg321_0.3.2.orig
 PKGNAME=	${DISTNAME:S/_/-/:S/.orig//}
+PKGREVISION=	1
 CATEGORIES=	audio
 MASTER_SITES=	${MASTER_SITE_SOURCEFORGE:=mpg321/}
 
Index: distinfo
===================================================================
RCS file: /cvsroot/pkgsrc/audio/mpg321/distinfo,v
retrieving revision 1.8
diff -u -p -r1.8 distinfo
--- distinfo	2 Jun 2016 09:18:19 -0000	1.8
+++ distinfo	16 Jun 2018 10:34:29 -0000
@@ -5,4 +5,4 @@ RMD160 (mpg321_0.3.2.orig.tar.gz) = 04ea
 SHA512 (mpg321_0.3.2.orig.tar.gz) = f1bead2c11e4cde0f1a87e1b2e3d216ef80c9a5dd8b219841961688d44a5fc63a54b7af07359766fde0b2712ddc5d0a90b20149c3228cb2d70e830e15c8ab234
 Size (mpg321_0.3.2.orig.tar.gz) = 151139 bytes
 SHA1 (patch-ao.c) = cb404acdfb032c5a823c717965d14319db0d4466
-SHA1 (patch-mpg321.c) = 0f82c72976ce1f1e7d16cd972eb1e38a0e305f86
+SHA1 (patch-mpg321.c) = c874219aa316899af42d5984ca06860642260d4b
Index: patches/patch-mpg321.c
===================================================================
RCS file: /cvsroot/pkgsrc/audio/mpg321/patches/patch-mpg321.c,v
retrieving revision 1.1
diff -u -p -r1.1 patch-mpg321.c
--- patches/patch-mpg321.c	2 Jun 2016 09:18:19 -0000	1.1
+++ patches/patch-mpg321.c	16 Jun 2018 10:34:29 -0000
@@ -1,6 +1,7 @@
 $NetBSD: patch-mpg321.c,v 1.1 2016/06/02 09:18:19 jperkin Exp $
 
-Ensure structs are zero'd before use.
+- Ensure structs are zero'd before use.
+- Do not unlock uninitialized main_lock
 
 --- mpg321.c.orig	2012-03-25 12:27:49.000000000 +0000
 +++ mpg321.c
@@ -12,3 +13,12 @@ Ensure structs are zero'd before use.
      playbuf.pl = pl = new_playlist();
  
      if (!pl)
+@@ -750,8 +751,6 @@ int main(int argc, char *argv[])
+ 	    	    if (tcgetattr(0, &terminal_settings) < 0)
+ 	    		    perror("tcgetattr()");
+ 	    	    memcpy(&old_terminal_settings, &terminal_settings, sizeof(struct termios));
+-		    /* Early thread start */
+-		    sem_post(&main_lock);
+ 	    }
+     }
+     /* Play the mpeg files or zip it! */