Update example/hashmaps/example_hashmaps_get_all_keys.f90

Co-authored-by: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>

Author: chuckyvt

example/hashmaps/example_hashmaps_get_all_keys.f90

@@ -1,8 +1,7 @@
 program example_hashmaps_get_all_keys
   use stdlib_kinds, only: int32
   use stdlib_hashmaps, only: chaining_hashmap_type
-  use stdlib_hashmap_wrappers, only: get, &
-                                     key_type, set
+  use stdlib_hashmap_wrappers, only: get, key_type, set
   implicit none
   type(chaining_hashmap_type) :: map
   type(key_type)   :: key