[PATCH] human: fix UMR introduced in recent change

[Pádraig Brady]

GCC 15 identifies this with:

lib/human.c: In function 'human_readable':
lib/human.c:295:32: warning: 'exponent_max' may be used uninitialized
  295 |             while (base <= amt && exponent < exponent_max);
      |                    ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

This issue also caused coreutils tests/dd/dd-stats.sh to fail

* lib/human.c (human_readable): Move initialization before
the gotos which might skip it.
---
 ChangeLog   | 6 ++++++
 lib/human.c | 9 +++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index b2f3d49805..98a9146cb9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2025-12-10  Pádraig Brady  <p...@draigbrady.com>
+
+       human: fix UMR introduced in recent change
+       * lib/human.c (human_readable): Move initialization before
+       the gotos which might skip it.
+
 2025-12-10  Bruno Haible  <br...@clisp.org>
 
        sigsegv: Reduce scope of local variables.
diff --git a/lib/human.c b/lib/human.c
index 9e2cf0958f..38eddaf53e 100644
--- a/lib/human.c
+++ b/lib/human.c
@@ -188,6 +188,11 @@ human_readable (uintmax_t n, char *buf, int opts,
      2 means adjusted N == AMT.TENTHS + 0.05;
      3 means AMT.TENTHS + 0.05 < adjusted N < AMT.TENTHS + 0.1.  */
   int rounding;
+
+  int exponent = -1;
+  int exponent_max = sizeof power_letter - 1;
+  char const *integerlim;
+
   if (to_block_size <= from_block_size)
     {
       if (from_block_size % to_block_size == 0)
@@ -213,10 +218,6 @@ human_readable (uintmax_t n, char *buf, int opts,
       goto use_integer_arithmetic;
     }
 
-  int exponent = -1;
-  int exponent_max = sizeof power_letter - 1;
-  char const *integerlim;
-
   {
     /* Either the result cannot be computed easily using uintmax_t,
        or from_block_size is zero.  Fall back on floating point.
-- 
2.51.1