Blackfin: delete fork func

We don't implement fork() since we are no-mmu, so redirect it to the
existing ENOSYS stub rather than adding a custom EINVAL one.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Bob Liu <lliubbo@gmail.com>

arch/blackfin/include/asm/unistd.h

@@ -11,7 +11,7 @@
  */
 #define __NR_restart_syscall	  0
 #define __NR_exit		  1
-#define __NR_fork		  2
+				/* 2 __NR_fork not supported on nommu */
 #define __NR_read		  3
 #define __NR_write		  4
 #define __NR_open		  5

arch/blackfin/kernel/entry.S

@@ -64,16 +64,6 @@ ENTRY(_ret_from_fork)
 	jump (p0);
 ENDPROC(_ret_from_fork)
 
-ENTRY(_sys_fork)
-	r0 = -EINVAL;
-#if (ANOMALY_05000371)
-	nop;
-	nop;
-	nop;
-#endif
-	rts;
-ENDPROC(_sys_fork)
-
 ENTRY(_sys_vfork)
 	r0 = sp;
 	r0 += 24;

arch/blackfin/mach-common/entry.S

@@ -1377,7 +1377,7 @@ END(_ex_table)
 ENTRY(_sys_call_table)
 	.long _sys_restart_syscall	/* 0 */
 	.long _sys_exit
-	.long _sys_fork
+	.long _sys_ni_syscall	/* fork */
 	.long _sys_read
 	.long _sys_write
 	.long _sys_open		/* 5 */