[RESEND PATCH v3 -next] fs: coredump: using preprocessor directives for dump_emit_page

[Hongyu Xie]

When CONFIG_COREDUMP is set and CONFIG_ELF_CORE is not set, you get warning
like:
fs/coredump.c:841:12: error: ‘dump_emit_page’ defined but not used
[-Werror=unused-function]
841 | static int dump_emit_page(struct coredump_params *cprm, struct
page *page)

dump_emit_page only called in dump_user_range, since dump_user_range
using #ifdef preprocessor directives, use #ifdef for dump_emit_page too.

Fixes: 06bbaa6dc53c ("[coredump] don't use __kernel_write() on kmap_local_page()")
Reported-by: k2ci <kernel-bot@xxxxxxxxxx>
Signed-off-by: Hongyu Xie <xiehongyu1@xxxxxxxxxx>
---
 fs/coredump.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/coredump.c b/fs/coredump.c
index de78bde2991b..95390a73b912 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -838,6 +838,7 @@ static int __dump_skip(struct coredump_params *cprm, size_t nr)
 	}
 }
 
+#ifdef CONFIG_ELF_CORE
 static int dump_emit_page(struct coredump_params *cprm, struct page *page)
 {
 	struct bio_vec bvec = {
@@ -870,6 +871,7 @@ static int dump_emit_page(struct coredump_params *cprm, struct page *page)
 
 	return 1;
 }
+#endif
 
 int dump_emit(struct coredump_params *cprm, const void *addr, int nr)
 {
-- 
2.34.1