drivers: target: Move prototype declaration of function to header file target_core_pr.h

Move prototype declaration of function
spc_parse_naa_6h_vendor_specific() from target_core_xcopy.c to header
file target_core_pr.h because it is used by more than one file.

This eliminates the following warning in target_core_spc.c:
drivers/target/target_core_spc.c:138:6: warning: no previous prototype for ‘spc_parse_naa_6h_vendor_specific’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <[e-mail]>
Reviewed-by: Josh Triplett <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>

drivers/target/target_core_pr.h

···
 #define PR_APTPL_MAX_IPORT_LEN			256
 #define PR_APTPL_MAX_TPORT_LEN			256
 
+/*
+ *  Function defined in target_core_spc.c
+ */
+void spc_parse_naa_6h_vendor_specific(struct se_device *, unsigned char *);
+
 extern struct kmem_cache *t10_pr_reg_cache;
 
 extern void core_pr_dump_initiator_port(struct t10_pr_registration *,

drivers/target/target_core_xcopy.c

···
 
 static struct workqueue_struct *xcopy_wq = NULL;
 /*
- * From target_core_spc.c
- */
-extern void spc_parse_naa_6h_vendor_specific(struct se_device *, unsigned char *);
-/*
  * From target_core_device.c
  */
 extern struct mutex g_device_mutex;