8057780: Fix ppc build after "8050147: StoreLoad barrier interferes with stack usages

Reviewed-by: kvn, shade
diff --git a/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp b/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
index a499a59..da8f444 100644
--- a/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
+++ b/hotspot/src/os_cpu/aix_ppc/vm/os_aix_ppc.cpp
@@ -564,7 +564,7 @@
 }
 #endif
 
-void os::extra_bang_size_in_bytes() {
+int os::extra_bang_size_in_bytes() {
   // PPC does not require the additional stack bang.
   return 0;
 }
diff --git a/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp b/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
index 14fc5f8..6a243c2 100644
--- a/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
+++ b/hotspot/src/os_cpu/linux_ppc/vm/os_linux_ppc.cpp
@@ -613,7 +613,7 @@
 }
 #endif
 
-int os:extra_bang_size_in_bytes() {
+int os::extra_bang_size_in_bytes() {
   // PPC does not require the additional stack bang.
   return 0;
 }