common: Fix call to xtrycalloc

[NIIBE Yutaka]

Hello,

While grep'ing use cases of calloc, I found a simple error in
strsplit.  Even if it's not correct, it works well (allocation of
memory can be larger, because of alignment requirement of element).

Here's a correction.

diff --git a/common/stringhelp.c b/common/stringhelp.c
index 576c2ea..38c3832 100644
--- a/common/stringhelp.c
+++ b/common/stringhelp.c
@@ -1230,7 +1230,7 @@ strsplit (char *string, char delim, char replacement, int *count)
   for (t = strchr (string, delim); t; t = strchr (t + 1, delim))
     fields ++;

-  result = xtrycalloc (sizeof (*result), (fields + 1));
+  result = xtrycalloc ((fields + 1), sizeof (*result));
   if (! result)
     return NULL;

--