regmap: use int type to store negative error codes

Change the 'ret' variable from unsigned int to int to store negative error
codes or zero returned by regmap_field_read() and regmap_read(), and change
'-1' to 'negative errno' in the comments.

Storing the negative error codes in unsigned type, doesn't cause an issue
at runtime but it's ugly as pants. Additionally, assigning negative error
codes to unsigned type may trigger a GCC warning when the -Wsign-conversion
flag is enabled.

No effect on runtime.

Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Message-ID: <20250828150702.193288-1-rongqianfeng@vivo.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: qianfengrong

drivers/base/regmap/regmap.c

@@ -2258,12 +2258,14 @@ EXPORT_SYMBOL_GPL(regmap_field_update_bits_base);
  * @field: Register field to operate on
  * @bits: Bits to test
  *
- * Returns -1 if the underlying regmap_field_read() fails, 0 if at least one of the
- * tested bits is not set and 1 if all tested bits are set.
+ * Returns negative errno if the underlying regmap_field_read() fails,
+ * 0 if at least one of the tested bits is not set and 1 if all tested
+ * bits are set.
  */
 int regmap_field_test_bits(struct regmap_field *field, unsigned int bits)
 {
-	unsigned int val, ret;
+	unsigned int val;
+	int ret;
 
 	ret = regmap_field_read(field, &val);
 	if (ret)
@@ -3309,7 +3311,8 @@ EXPORT_SYMBOL_GPL(regmap_update_bits_base);
  */
 int regmap_test_bits(struct regmap *map, unsigned int reg, unsigned int bits)
 {
-	unsigned int val, ret;
+	unsigned int val;
+	int ret;
 
 	ret = regmap_read(map, reg, &val);
 	if (ret)