[AX.25]: Make asc2ax() thread-proof

Asc2ax was still using a static buffer for all invocations which isn't
exactly SMP-safe.  Change asc2ax to take an additional result buffer as
the argument.  Change all callers to provide such a buffer.

This one only really is a fix for ROSE and as per recent discussions
there's still much more to fix in ROSE ...

Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ax25.h b/include/net/ax25.h
index 364b046..227d337 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -258,7 +258,7 @@
 /* ax25_addr.c */
 extern ax25_address null_ax25_address;
 extern char *ax2asc(char *buf, ax25_address *);
-extern ax25_address *asc2ax(char *);
+extern void asc2ax(ax25_address *addr, char *callsign);
 extern int  ax25cmp(ax25_address *, ax25_address *);
 extern int  ax25digicmp(ax25_digi *, ax25_digi *);
 extern unsigned char *ax25_addr_parse(unsigned char *, int, ax25_address *, ax25_address *, ax25_digi *, int *, int *);