toolbar: Use snprintf for elm,number,item buffer handling
toolbar: Use snprintf for elm,number,item buffer handling

Avoid potential buffer overflow

Signed-off-by: Daniel Willmann <a5171b3a1085e70fffc1f019415619b488fe20e6@samsung.com>

rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,tasn/elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,FlorentRevest/Elementary,rvandegrift/elementary,rvandegrift/elementary,FlorentRevest/Elementary