Documentation: rename addr_in_gen_pool to gen_pool_has_addr

Update the document, since we have renamed addr_in_gen_pool to
gen_pool_has_addr.

Link: http://lkml.kernel.org/r/20181229015914.5573-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/Documentation/core-api/genalloc.rst b/Documentation/core-api/genalloc.rst
index 6b38a39..a534cc7 100644
--- a/Documentation/core-api/genalloc.rst
+++ b/Documentation/core-api/genalloc.rst
@@ -129,7 +129,7 @@
    :functions: gen_pool_for_each_chunk
 
 .. kernel-doc:: lib/genalloc.c
-   :functions: addr_in_gen_pool
+   :functions: gen_pool_has_addr
 
 .. kernel-doc:: lib/genalloc.c
    :functions: gen_pool_avail