Fix mixed-use-of-spaces-and-tabs rpmlint warning

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Germano Massullo <germano.massullo@gmail.com>
Closes #17461

Author: Germano0

rpm/generic/zfs.spec.in

@@ -275,7 +275,7 @@ validating the file system.
 %package dracut
 Summary:        Dracut module
 Group:          System Environment/Kernel
-BuildArch:	noarch
+BuildArch:      noarch
 Requires:       %{name} >= %{version}
 Requires:       dracut
 Requires:       /usr/bin/awk