fix typo in the s390/s390x inclusion

the typo meant that some C files were not included in the build, which caused the published version of this crate to fail for s390x targets

Author: folkertdev

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "libz-sys"
-version = "1.1.18"
+version = "1.1.19"
 authors = [
     "Alex Crichton <[email protected]>",
     "Josh Triplett <[email protected]>",
@@ -30,7 +30,7 @@ include = [
     "src/zlib-ng/arch/generic/**.[ch]",
     "src/zlib-ng/arch/power/**.[ch]",
     "src/zlib-ng/arch/riscv/**.[ch]",
-    "src/zlib-ng/arch/s390x/**.[ch]",
+    "src/zlib-ng/arch/s390/**.[ch]",
     "src/zlib-ng/arch/x86/**.[ch]",
     "src/zlib-ng/*.[ch].in",
     "src/zlib-ng/*.pc.in",