staging: vt6655: Convert macro vt6655_mac_clear_stck_ds to function

Convert once used macro to static function. Multiline macros are not
liked by kernel community. Rename variable byOrgValue to reg_value to
avoid CamelCase which is not accepted by checkpatch.pl. Change variable
declaration to u8 as this improves readability.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/cbfe5cc170b68564ff45bb7f45c63de241c2a664.1658986804.git.philipp.g.hortmann@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Philipp Hortmann

drivers/staging/vt6655/mac.c

@@ -70,6 +70,15 @@ void vt6655_mac_word_reg_bits_off(void __iomem *iobase, const u8 reg_offset, con
 	iowrite16(reg_value & ~(bit_mask), iobase + reg_offset);
 }
 
+static void vt6655_mac_clear_stck_ds(void __iomem *iobase)
+{
+	u8 reg_value;
+
+	reg_value = ioread8(iobase + MAC_REG_STICKHW);
+	reg_value = reg_value & 0xFC;
+	iowrite8(reg_value, iobase + MAC_REG_STICKHW);
+}
+
 /*
  * Description:
  *      Test if all test bits off

drivers/staging/vt6655/mac.h

@@ -577,14 +577,6 @@ do {									\
 		iowrite32(DMACTL_RUN, iobase + MAC_REG_AC0DMACTL);	\
 } while (0)
 
-#define vt6655_mac_clear_stck_ds(iobase)				\
-do {									\
-	unsigned char byOrgValue;					\
-	byOrgValue = ioread8(iobase + MAC_REG_STICKHW);			\
-	byOrgValue = byOrgValue & 0xFC;					\
-	iowrite8(byOrgValue, iobase + MAC_REG_STICKHW);			\
-} while (0)
-
 #define MACvSelectPage0(iobase)				\
 	iowrite8(0, iobase + MAC_REG_PAGE1SEL)