efi/printf: Drop %n format and L qualifier

%n is unused and deprecated.

The L qualifer is parsed but not actually implemented.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-7-nivedita@alum.mit.eduSigned-off-by: Ard Biesheuvel <ardb@kernel.org>

drivers/firmware/efi/libstub/vsprintf.c

@@ -127,7 +127,7 @@ int vsprintf(char *buf, const char *fmt, va_list args)
 	int field_width;	/* width of output field */
 	int precision;		/* min. # of digits for integers; max
 				   number of chars for from string */
-	int qualifier;		/* 'h', 'l', or 'L' for integer fields */
+	int qualifier;		/* 'h' or 'l' for integer fields */
 
 	for (str = buf; *fmt; ++fmt) {
 		if (*fmt != '%') {
@@ -188,7 +188,7 @@ int vsprintf(char *buf, const char *fmt, va_list args)
 
 		/* get the conversion qualifier */
 		qualifier = -1;
-		if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') {
+		if (*fmt == 'h' || *fmt == 'l') {
 			qualifier = *fmt;
 			++fmt;
 		}
@@ -229,16 +229,6 @@ int vsprintf(char *buf, const char *fmt, va_list args)
 				     field_width, precision, flags);
 			continue;
 
-		case 'n':
-			if (qualifier == 'l') {
-				long *ip = va_arg(args, long *);
-				*ip = (str - buf);
-			} else {
-				int *ip = va_arg(args, int *);
-				*ip = (str - buf);
-			}
-			continue;
-
 		case '%':
 			*str++ = '%';
 			continue;