drm/amd/display: Add gnu_printf format attribute for snprintf_count()

Fix the following W=1 kernel build warning:

display/dc/dcn10/dcn10_hw_sequencer_debug.c: In function ‘snprintf_count’:
display/dc/dcn10/dcn10_hw_sequencer_debug.c:56:2: warning: function ‘snprintf_count’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]

Use the __printf() attribute to let the compiler warn if
invalid format strings are passed in.

And fix the following checks:

CHECK: Avoid CamelCase: <pBuf> +unsigned int __printf(3, 4)
snprintf_count(char *pBuf, unsigned int bufSize, char *fmt, ...)

CHECK: Avoid CamelCase: <bufSize> +unsigned int __printf(3, 4)
snprintf_count(char *pBuf, unsigned int bufSize, char *fmt, ...)

Cc: Hamza Mahfooz <hamza.mahfooz@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer_debug.c

@@ -45,7 +45,8 @@
 #include "dcn10_cm_common.h"
 #include "clk_mgr.h"
 
-unsigned int snprintf_count(char *pBuf, unsigned int bufSize, char *fmt, ...)
+__printf(3, 4)
+unsigned int snprintf_count(char *pbuf, unsigned int bufsize, char *fmt, ...)
 {
 	int ret_vsnprintf;
 	unsigned int chars_printed;
@@ -53,15 +54,15 @@ unsigned int snprintf_count(char *pBuf, unsigned int bufSize, char *fmt, ...)
 	va_list args;
 	va_start(args, fmt);
 
-	ret_vsnprintf = vsnprintf(pBuf, bufSize, fmt, args);
+	ret_vsnprintf = vsnprintf(pbuf, bufsize, fmt, args);
 
 	va_end(args);
 
 	if (ret_vsnprintf > 0) {
-		if (ret_vsnprintf < bufSize)
+		if (ret_vsnprintf < bufsize)
 			chars_printed = ret_vsnprintf;
 		else
-			chars_printed = bufSize - 1;
+			chars_printed = bufsize - 1;
 	} else
 		chars_printed = 0;