maint: df: avoid sizeof(char**) static analysis warning

* src/df.c (alloc_table_row): Use the size of char** to enlarge
the table.  Spotted by Coverity.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/df.c b/src/df.c
index 3036c74ab..e7639434e 100644
--- a/src/df.c
+++ b/src/df.c
@@ -290,7 +290,7 @@ static void
 alloc_table_row (void)
 {
   nrows++;
-  table = xnrealloc (table, nrows, sizeof (char *));
+  table = xnrealloc (table, nrows, sizeof (char **));
   table[nrows - 1] = xnmalloc (ncolumns, sizeof (char *));
 }