[PATCH] vdso: Fix powerpc build U64_MAX undeclared error

[Adrian Hunter <adrian.hunter@intel.com>]

U64_MAX is not in include/vdso/limits.h, although that isn't noticed on x86
because x86 includes include/linux/limits.h indirectly. However powerpc
is more selective, resulting in the following build error:

  In file included from <command-line>:
  lib/vdso/gettimeofday.c: In function 'vdso_calc_ns':
  lib/vdso/gettimeofday.c:11:33: error: 'U64_MAX' undeclared
     11 | # define VDSO_DELTA_MASK(vd)    U64_MAX
        |                                 ^~~~~~~

Use ULLONG_MAX instead which will work just as well and is in
include/vdso/limits.h.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20240409124905.6816db37@canb.auug.org.au/
Fixes: c8e3a8b6f2e6 ("vdso: Consolidate vdso_calc_delta()")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 lib/vdso/gettimeofday.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 9c3a8d2440c9..899850bd6f0b 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -8,7 +8,7 @@
 #ifndef vdso_calc_ns
 
 #ifdef VDSO_DELTA_NOMASK
-# define VDSO_DELTA_MASK(vd)	U64_MAX
+# define VDSO_DELTA_MASK(vd)	ULLONG_MAX
 #else
 # define VDSO_DELTA_MASK(vd)	(vd->mask)
 #endif
-- 
2.34.1