Merge branch 'ds/sparse-cone'

Code cleanup.

* ds/sparse-cone:
  Documentation/git-sparse-checkout.txt: fix a typo
  sparse-checkout: use extern for global variables

Author: gitster

Documentation/git-sparse-checkout.txt

@@ -5,7 +5,7 @@ NAME
 ----
 git-sparse-checkout - Initialize and modify the sparse-checkout
 configuration, which reduces the checkout to a set of paths
-given by a list of atterns.
+given by a list of patterns.
 
 
 SYNOPSIS

cache.h

@@ -958,8 +958,8 @@ extern int protect_hfs;
 extern int protect_ntfs;
 extern const char *core_fsmonitor;
 
-int core_apply_sparse_checkout;
-int core_sparse_checkout_cone;
+extern int core_apply_sparse_checkout;
+extern int core_sparse_checkout_cone;
 
 /*
  * Include broken refs in all ref iterations, which will