[PATCH v3] xen/decompress: resolve MISRA R5.5 identifier/macro name conflicts

[Dmytro Prokopchuk1 <dmytro_prokopchuk1@xxxxxxxx>]

Convert 'free' macro in 'decompress.h' from object-like to function-like
form.

The object-like macro '#define free xfree' performs unconditional text
replacement, causing conflicts with identifiers named 'free', such as
struct fields in 'page_info' unions defined in 'xen/arch/arm/include/asm/mm.h'.
Function-like macros only match when followed by parentheses, allowing
'free' to be used both as a macro and as a struct field without conflicts.

Applying function-like form to 'malloc', 'large_malloc' and 'large_free'
ensures consistent macro style.

Additionally moved 'large_{malloc,free}' past the #endif to reduce
redundancy.

While function-like macros prevent uses where the underlying function
identifier is needed directly, such as taking a function pointer, no
such uses exist in the current Xen codebase.

Signed-off-by: Dmytro Prokopchuk <dmytro_prokopchuk1@xxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Changes in v3:
- updated wording of the last paragraph in the commit message
- large_{malloc,free} moved past the #endif
- changed macro parameters naming ('s', 'p')
- added Jan's Acked-by
Link to v2:
- 
https://patchew.org/Xen/025bc771fe1339dfae476037af86c6bfa1048382.1779654114.git.dmytro._5Fprokopchuk1@xxxxxxxx/
Changes in v2:
- converted other macros for consistency
- updated commit message wording
---
 xen/common/decompress.h | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/xen/common/decompress.h b/xen/common/decompress.h
index 034c833665..b347d91980 100644
--- a/xen/common/decompress.h
+++ b/xen/common/decompress.h
@@ -9,11 +9,8 @@
 #include <xen/types.h>
 #include <xen/xmalloc.h>
 
-#define malloc xmalloc_bytes
-#define free xfree
-
-#define large_malloc xmalloc_bytes
-#define large_free xfree
+#define malloc(s) xmalloc_bytes(s)
+#define free(p) xfree(p)
 
 #else
 
@@ -21,9 +18,9 @@
 #define __init
 #define __initdata
 
-#define large_malloc malloc
-#define large_free free
-
 #endif
 
+#define large_malloc(s) malloc(s)
+#define large_free(p) free(p)
+
 #endif /* DECOMPRESS_H */
-- 
2.43.0