check-zstd-symbols: also ignore __pfx_ symbols

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b341b20d648bb7e9a3307c33163e7399f0913e66

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes openzfs#15282 
Closes openzfs#15284

module/Makefile.in

@@ -168,4 +168,4 @@ gen-zstd-symbols:
 	for obj in $(addprefix zstd/,$(ZSTD_UPSTREAM_OBJS)); do echo; echo "/* $${obj#zstd/}: */"; @OBJDUMP@ -t $$obj | awk '$$2 == "g" && !/ zfs_/ {print "#define\t" $$6 " zfs_" $$6}' | sort; done >> zstd/include/zstd_compat_wrapper.h
 
 check-zstd-symbols:
-	@OBJDUMP@ -t $(addprefix zstd/,$(ZSTD_UPSTREAM_OBJS)) | awk '/file format/ {print}  $$2 == "g" && !/ zfs_/ {++ret; print}  END {exit ret}'
+	@OBJDUMP@ -t $(addprefix zstd/,$(ZSTD_UPSTREAM_OBJS)) | awk '/file format/ {print}  $$2 == "g" && (!/ zfs_/ && !/ __pfx_zfs_/) {++ret; print}  END {exit ret}'