PNP: isapnp: remove defined but not used function 'isapnp_checksum'

Fix gcc '-Wunused-function' warnning:

drivers/pnp/isapnp/core.c:752:29: warning: 'isapnp_checksum' defined but
not used [-Wunused-function]
752 | static unsigned char __init isapnp_checksum(unsigned char *data)

Commit 04c589f3 ("PNP: isapnp: remove set but not used variable
'checksum'") removes the last caller of the function. It is never used
and so can be removed.

Fixes: 04c589f3 ("PNP: isapnp: remove set but not used variable 'checksum'")
Signed-off-by: yu kuai <yukuai3@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/pnp/isapnp/core.c

@@ -746,28 +746,6 @@ static void __init isapnp_parse_resource_map(struct pnp_card *card)
 	}
 }
 
-/*
- *  Compute ISA PnP checksum for first eight bytes.
- */
-static unsigned char __init isapnp_checksum(unsigned char *data)
-{
-	int i, j;
-	unsigned char checksum = 0x6a, bit, b;
-
-	for (i = 0; i < 8; i++) {
-		b = data[i];
-		for (j = 0; j < 8; j++) {
-			bit = 0;
-			if (b & (1 << j))
-				bit = 1;
-			checksum =
-			    ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
-			    | (checksum >> 1);
-		}
-	}
-	return checksum;
-}
-
 /*
  *  Build device list for all present ISA PnP devices.
  */