ARM: 9135/1: kprobes: address gcc -Wempty-body warning

Building with 'make W=1' shows a warning in some configurations
when 'verbose()' is defined to be empty.

arch/arm/probes/kprobes/test-core.c: In function 'kprobes_test_case_start':
arch/arm/probes/kprobes/test-core.c:1367:26: error: suggest braces around empty body in an 'else' statement [-Werror=empty-body]
 1367 |      current_instruction);
      |                          ^

Change the definition of verbose() to use no_printk(), allowing format
string checking and avoiding the warning.

Link: https://lore.kernel.org/all/20210322114600.3528031-1-arnd@kernel.org/Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

arch/arm/probes/kprobes/test-core.h

@@ -98,7 +98,7 @@ struct test_arg_end {
 #if VERBOSE
 #define verbose(fmt, ...) pr_info(fmt, ##__VA_ARGS__)
 #else
-#define verbose(fmt, ...)
+#define verbose(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
 #endif
 
 #define TEST_GROUP(title)					\