s390/kdump: fix compile for !SMP

Fix this compile error:

arch/s390/kernel/setup.c:875:2: error:
 implicit declaration of function 'smp_save_dump_cpus'

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index 4098306..5df26b1 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -55,6 +55,7 @@
 static inline int smp_vcpu_scheduled(int cpu) { return 1; }
 static inline void smp_yield_cpu(int cpu) { }
 static inline void smp_fill_possible_mask(void) { }
+static inline void smp_save_dump_cpus(void) { }
 
 #endif /* CONFIG_SMP */
 
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 24ad89d..6f54c17 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -560,6 +560,25 @@
 	memblock_free(vx_sa, PAGE_SIZE);
 }
 
+int smp_store_status(int cpu)
+{
+	unsigned long vx_sa;
+	struct pcpu *pcpu;
+
+	pcpu = pcpu_devices + cpu;
+	if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
+			      0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
+		return -EIO;
+	if (!MACHINE_HAS_VX)
+		return 0;
+	vx_sa = __pa(pcpu->lowcore->vector_save_area_addr);
+	__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
+			  vx_sa, NULL);
+	return 0;
+}
+
+#endif /* CONFIG_CRASH_DUMP */
+
 /*
  * Collect CPU state of the previous, crashed system.
  * There are four cases:
@@ -589,6 +608,7 @@
  */
 void __init smp_save_dump_cpus(void)
 {
+#ifdef CONFIG_CRASH_DUMP
 	int addr, cpu, boot_cpu_addr, max_cpu_addr;
 	struct save_area_ext *sa_ext;
 	bool is_boot_cpu;
@@ -629,30 +649,8 @@
 	}
 	diag308_reset();
 	pcpu_set_smt(0);
-}
-
-int smp_store_status(int cpu)
-{
-	unsigned long vx_sa;
-	struct pcpu *pcpu;
-
-	pcpu = pcpu_devices + cpu;
-	if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
-			      0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
-		return -EIO;
-	if (!MACHINE_HAS_VX)
-		return 0;
-	vx_sa = __pa(pcpu->lowcore->vector_save_area_addr);
-	__pcpu_sigp_relax(pcpu->address, SIGP_STORE_ADDITIONAL_STATUS,
-			  vx_sa, NULL);
-	return 0;
-}
-
-#else
-void smp_save_dump_cpus(void)
-{
-}
 #endif /* CONFIG_CRASH_DUMP */
+}
 
 void smp_cpu_set_polarization(int cpu, int val)
 {