staging: speakup: str initialization replaced with NULL where it was initialized with int

Fixed warnings in all of three files where the string was initilized with an integer instead of NULL

Signed-off-by: Shalin Mehta <shalinmehta85@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/speakup/main.c b/drivers/staging/speakup/main.c
index 14079c4..47502fa 100644
--- a/drivers/staging/speakup/main.c
+++ b/drivers/staging/speakup/main.c
@@ -90,7 +90,7 @@
 	{"repeats", "()", CH_RPT},
 	{"extended numeric", "", B_EXNUM},
 	{"symbols", "", B_SYM},
-	{0, 0}
+	{NULL, NULL}
 };
 
 static char mark_cut_flag;
diff --git a/drivers/staging/speakup/speakup_audptr.c b/drivers/staging/speakup/speakup_audptr.c
index 3508aee..61a3cee 100644
--- a/drivers/staging/speakup/speakup_audptr.c
+++ b/drivers/staging/speakup/speakup_audptr.c
@@ -39,7 +39,7 @@
 	{ RATE, .u.n = {"\x05[r%d]", 10, 0, 20, 100, -10, NULL } },
 	{ PITCH, .u.n = {"\x05[f%d]", 80, 39, 4500, 0, 0, NULL } },
 	{ VOL, .u.n = {"\x05[g%d]", 21, 0, 40, 0, 0, NULL } },
-	{ TONE, .u.n = {"\x05[s%d]", 9, 0, 63, 0, 0, 0 } },
+	{ TONE, .u.n = {"\x05[s%d]", 9, 0, 63, 0, 0, NULL } },
 	{ PUNCT, .u.n = {"\x05[A%c]", 0, 0, 3, 0, 0, "nmsa" } },
 	{ DIRECT, .u.n = {NULL, 0, 0, 1, 0, 0, NULL } },
 	V_LAST_VAR
diff --git a/drivers/staging/speakup/varhandlers.c b/drivers/staging/speakup/varhandlers.c
index 9aa2a78..70231b6 100644
--- a/drivers/staging/speakup/varhandlers.c
+++ b/drivers/staging/speakup/varhandlers.c
@@ -46,7 +46,7 @@
 	{ "direct", DIRECT, VAR_NUM, NULL, NULL },
 };
 
-static struct st_var_header *var_ptrs[MAXVARS] = { 0, 0, 0 };
+static struct st_var_header *var_ptrs[MAXVARS] = { NULL, NULL, NULL };
 
 static struct punc_var_t punc_vars[] = {
 	{ PUNC_SOME, 1 },