staging: fbtft: fix do not initialise statics to 0 or NULL

This patch fixes the following checkpatch.pl error:
fix do not initialise statics to 0 or NULL
Signed-off-by: Heba Aamer <heba93aamer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fbtft/fb_pcd8544.c

@@ -36,7 +36,7 @@
 #define TXBUFLEN       (84*6)
 #define DEFAULT_GAMMA  "40" /* gamma is used to control contrast in this driver */
 
-static unsigned tc = 0;
+static unsigned tc;
 module_param(tc, uint, 0);
 MODULE_PARM_DESC(tc, "TC[1:0] Temperature coefficient: 0-3 (default: 0)");