[ISAPNP] Remove uneeded MOD_INC/DEC_USE_COUNT

isapnp_cfg_begin and isapnp_cfg_end are exported symbols, so if any
module using them is loaded isapnp.o can't be unloaded anyway

drivers/pnp/isapnp/core.c

@@ -932,7 +932,6 @@ int isapnp_cfg_begin(int csn, int logdev)
 {
 	if (csn < 1 || csn > isapnp_csn_count || logdev > 10)
 		return -EINVAL;
-	MOD_INC_USE_COUNT;
 	down(&isapnp_cfg_mutex);
 	isapnp_wait();
 	isapnp_key();
@@ -960,7 +959,6 @@ int isapnp_cfg_end(void)
 {
 	isapnp_wait();
 	up(&isapnp_cfg_mutex);
-	MOD_DEC_USE_COUNT;
 	return 0;
 }