btrfs-progs: fix typos in restore help/doc

Signed-off-by: David Sterba <dsterba@suse.cz>

Documentation/btrfs-restore.asciidoc

@@ -68,7 +68,7 @@ restore only filenames matching regex, you have to use following syntax (possibl
 +^/(|home(|/username(|/Desktop(|/.*))))$+
 
 -c::
-ignore case (--path-regrex only).
+ignore case (--path-regex only).
 
 EXIT STATUS
 -----------

cmds-restore.c

@@ -1257,7 +1257,7 @@ const char * const cmd_restore_usage[] = {
 	"                restore only filenames matching regex,",
 	"                you have to use following syntax (possibly quoted):",
 	"                ^/(|home(|/username(|/Desktop(|/.*))))$",
-	"-c              ignore case (--path-regrex only)",
+	"-c              ignore case (--path-regex only)",
 	NULL
 };