Fix Clang build

Change-Id: I0b51699c0a1368cf5813bd9d3cd4479139d23d6a

src/fmm.c

@@ -277,6 +277,7 @@ static inline HsaSharedMemoryStruct *to_hsa_shared_memory_struct(
 	return (HsaSharedMemoryStruct *)SharedMemoryHandle;
 }
 
+__attribute__((unused))
 static inline HsaSharedMemoryHandle *to_hsa_shared_memory_handle(
 			HsaSharedMemoryStruct *SharedMemoryStruct)
 {

src/libhsakmt.h

@@ -67,7 +67,7 @@ extern int PAGE_SHIFT;
 #define ALIGN_UP(x,align) (((uint64_t)(x) + (align) - 1) & ~(uint64_t)((align)-1))
 #define ALIGN_UP_32(x,align) (((uint32_t)(x) + (align) - 1) & ~(uint32_t)((align)-1))
 #define PAGE_ALIGN_UP(x) ALIGN_UP(x,PAGE_SIZE)
-#define BITMASK(n) (((n) < sizeof(1ULL) * CHAR_BIT ? (1ULL << (n)) : 0) - 1ULL)
+#define BITMASK(n) ((n) ? (UINT64_MAX >> (sizeof(UINT64_MAX) * CHAR_BIT - n)) : n)
 #define ARRAY_LEN(array) (sizeof(array) / sizeof(array[0]))
 
 /* HSA Thunk logging usage */