lib/vsprintf: allow printing upper case GUIDs

In the UEFI context GUIDs are expected to be rendered in upper case.

The patch uses the formerly unused bit 1 of the parameter str_format
of function uuid_bin_to_str() to indicate if we need upper or lower case
output.

Function uuid_string() in vsprint.c is adjusted to correctly set the bit
depending on the print format code.

%pUb: 01020304-0506-0708-090a-0b0c0d0e0f10
%pUB: 01020304-0506-0708-090A-0B0C0D0E0F10
%pUl: 04030201-0605-0807-090a-0b0c0d0e0f10
%pUL: 04030201-0605-0807-090A-0B0C0D0E0F10

Up to this point only a diagnostic message in mount_ubifs() using '%pUB' is
concerned by the change. Further patches are needed to adjust the UEFI
subsystem.

A unit test is provided inside the ut_print command.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 8bbbd48..425f2f5 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -383,29 +383,31 @@
 
 #ifdef CONFIG_LIB_UUID
 /*
- * This works (roughly) the same way as linux's, but we currently always
- * print lower-case (ie. we just keep %pUB and %pUL for compat with linux),
- * mostly just because that is what uuid_bin_to_str() supports.
+ * This works (roughly) the same way as Linux's.
  *
  *   %pUb:   01020304-0506-0708-090a-0b0c0d0e0f10
+ *   %pUB:   01020304-0506-0708-090A-0B0C0D0E0F10
  *   %pUl:   04030201-0605-0807-090a-0b0c0d0e0f10
+ *   %pUL:   04030201-0605-0807-090A-0B0C0D0E0F10
  */
 static char *uuid_string(char *buf, char *end, u8 *addr, int field_width,
 			 int precision, int flags, const char *fmt)
 {
 	char uuid[UUID_STR_LEN + 1];
-	int str_format = UUID_STR_FORMAT_STD;
+	int str_format;
 
 	switch (*(++fmt)) {
 	case 'L':
+		str_format = UUID_STR_FORMAT_GUID | UUID_STR_UPPER_CASE;
+		break;
 	case 'l':
 		str_format = UUID_STR_FORMAT_GUID;
 		break;
 	case 'B':
-	case 'b':
-		/* this is the default */
+		str_format = UUID_STR_FORMAT_STD | UUID_STR_UPPER_CASE;
 		break;
 	default:
+		str_format = UUID_STR_FORMAT_STD;
 		break;
 	}