<linux/cleanup.h>: Allow the passing of both iomem and non-iomem pointers to no_free_ptr()

Calling no_free_ptr() for an __iomem pointer results in Sparse
complaining about the types:

  warning: incorrect type in argument 1 (different address spaces)
     expected void const volatile *val
     got void [noderef] __iomem *__val

[ The example is from drivers/platform/x86/intel/pmc/core_ssram.c:283 ]

The problem is caused by the signature of __must_check_fn() added in:

  85be6d8 ("cleanup: Make no_free_ptr() __must_check")

... to enforce that the return value is always used.

Use __force to allow both iomem and non-iomem pointers to be given for
no_free_ptr().

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

Author: ij-intel

include/linux/cleanup.h

@@ -212,7 +212,7 @@ const volatile void * __must_check_fn(const volatile void *val)
 { return val; }
 
 #define no_free_ptr(p) \
-	((typeof(p)) __must_check_fn(__get_and_null(p, NULL)))
+	((typeof(p)) __must_check_fn((__force const volatile void *)__get_and_null(p, NULL)))
 
 #define return_ptr(p)	return no_free_ptr(p)