[PATCH v2] staging: sm750fb: fix unused tmp in sw_i2c_wait

[Sun Jian <sun.jian.kdev@gmail.com>]

clang W=1 warns that 'tmp' is set but not used in sw_i2c_wait().

sw_i2c_wait() provides the delay between bit-banged I2C GPIO transitions.
Replace the loop-count delay with a time-based udelay(1) to avoid CPU-
dependent timing and fix the warning.

Compile-tested with clang W=1; no hardware available to validate timing.

Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
---
v2:
- Replace cpu_relax() delay loop with time-based udelay(1) to avoid
  CPU-dependent timing (per Greg's feedback).

v1:
- Used cpu_relax() in the loop to silence -Wunused-but-set-variable.
---
 drivers/staging/sm750fb/ddk750_swi2c.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index 0ef8d4ff2ef9..d5843fa69bfa 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -11,6 +11,7 @@
 #include "ddk750_reg.h"
 #include "ddk750_swi2c.h"
 #include "ddk750_power.h"
+#include <linux/delay.h>
 
 /*
  * I2C Software Master Driver:
@@ -92,12 +93,7 @@ static void sw_i2c_wait(void)
      * it's more reliable than counter loop ..
      * write 0x61 to 0x3ce and read from 0x3cf
      */
-	int i, tmp;
-
-	for (i = 0; i < 600; i++) {
-		tmp = i;
-		tmp += i;
-	}
+	udelay(1);
 }
 
 /*
-- 
2.43.0