sparc64: fix sparse warning in tsb.c

Fix following warning:
tsb.c:290:5: warning: symbol 'sysctl_tsb_ratio' was not declared. Should it be static?

Add extern declaration in asm/setup.h and remove local declaration
in kernel/sysctl.c
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/setup.h

@@ -52,6 +52,7 @@ unsigned long safe_compute_effective_address(struct pt_regs *, unsigned int);
 int handle_ldf_stq(u32 insn, struct pt_regs *regs);
 void handle_ld_nf(u32 insn, struct pt_regs *regs);
 
+extern int sysctl_tsb_ratio;
 #endif
 
 void sun_do_break(void);

arch/sparc/mm/tsb.c

@@ -9,6 +9,7 @@
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/mmu_context.h>
+#include <asm/setup.h>
 #include <asm/tsb.h>
 #include <asm/tlb.h>
 #include <asm/oplib.h>

kernel/sysctl.c

@@ -152,10 +152,6 @@ static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
 #ifdef CONFIG_SPARC
 #endif
 
-#ifdef CONFIG_SPARC64
-extern int sysctl_tsb_ratio;
-#endif
-
 #ifdef __hppa__
 extern int pwrsw_enabled;
 #endif