net: When checking prerequisites, consider boot_file_name

For net_boot_common, we allow the serverip to be specified as part of
the boot file name. For net commands that require serverip, include that
source as a valid specification of serverip.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Alexander Graf <agraf@suse.de>

include/net.h

@@ -839,6 +839,9 @@ ushort env_get_vlan(char *);
 /* copy a filename (allow for "..." notation, limit length) */
 void copy_filename(char *dst, const char *src, int size);
 
+/* check if serverip is specified in filename from the command line */
+int is_serverip_in_cmd(void);
+
 /* get a random source port */
 unsigned int random_port(void);