raid6/test: fix a compilation warning

The compilation warning is redefination showed as following:

        In file included from tables.c:2:
        ../../../include/linux/export.h:180: warning: "EXPORT_SYMBOL" redefined
         #define EXPORT_SYMBOL(sym)  __EXPORT_SYMBOL(sym, "")

        In file included from tables.c:1:
        ../../../include/linux/raid/pq.h:61: note: this is the location of the previous definition
         #define EXPORT_SYMBOL(sym)

Fixes: 69a94abb ("export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols")
Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Song Liu <songliubraving@fb.com>

include/linux/raid/pq.h

@@ -58,7 +58,9 @@ extern const char raid6_empty_zero_page[PAGE_SIZE];
 #define enable_kernel_altivec()
 #define disable_kernel_altivec()
 
+#undef	EXPORT_SYMBOL
 #define EXPORT_SYMBOL(sym)
+#undef	EXPORT_SYMBOL_GPL
 #define EXPORT_SYMBOL_GPL(sym)
 #define MODULE_LICENSE(licence)
 #define MODULE_DESCRIPTION(desc)

lib/raid6/mktables.c

@@ -56,8 +56,8 @@ int main(int argc, char *argv[])
 	uint8_t v;
 	uint8_t exptbl[256], invtbl[256];
 
-	printf("#include <linux/raid/pq.h>\n");
 	printf("#include <linux/export.h>\n");
+	printf("#include <linux/raid/pq.h>\n");
 
 	/* Compute multiplication table */
 	printf("\nconst u8  __attribute__((aligned(256)))\n"