jfsutils: flush stdout before waiting for user input.

fixes #18499.

srcpkgs/jfsutils/patches/flush-before-read-musl.patch

@@ -0,0 +1,12 @@
+diff --git mkfs/mkfs.c mkfs/mkfs.c
+index 3a1d628..bf0caff 100644
+--- mkfs/mkfs.c
++++ mkfs/mkfs.c
+@@ -924,6 +924,7 @@ int main(int argc, char *argv[])
+                }
+                do {
+                        printf("\nContinue? (Y/N) ");
++                       fflush(stdout);
+                        c = getchar();
+ 
+                        if (c == 'n' || c == 'N') {

srcpkgs/jfsutils/template

@@ -1,7 +1,7 @@
 # Template file for 'jfsutils'
 pkgname=jfsutils
 version=1.1.15
-revision=2
+revision=3
 build_style=gnu-configure
 makedepends="libuuid-devel"
 short_desc="JFS filesystem utilities"