cxl/core/regs: Fix usage of map->reg_type in cxl_decode_regblock() before assigned

In the error path, map->reg_type is being used for kernel warning
before its value is setup. Found by code inspection. Exposure to
user is wrong reg_type being emitted via kernel log. Use a local
var for reg_type and retrieve value for usage.

Fixes: 6c7f4f1 ("cxl/core/regs: Make cxl_map_{component, device}_regs() device generic")
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: davejiang

drivers/cxl/core/regs.c

@@ -271,18 +271,19 @@ EXPORT_SYMBOL_NS_GPL(cxl_map_device_regs, CXL);
 static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi,
 				struct cxl_register_map *map)
 {
+	u8 reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo);
 	int bar = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo);
 	u64 offset = ((u64)reg_hi << 32) |
 		     (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK);
 
 	if (offset > pci_resource_len(pdev, bar)) {
 		dev_warn(&pdev->dev,
 			 "BAR%d: %pr: too small (offset: %pa, type: %d)\n", bar,
-			 &pdev->resource[bar], &offset, map->reg_type);
+			 &pdev->resource[bar], &offset, reg_type);
 		return false;
 	}
 
-	map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo);
+	map->reg_type = reg_type;
 	map->resource = pci_resource_start(pdev, bar) + offset;
 	map->max_size = pci_resource_len(pdev, bar) - offset;
 	return true;