[glibc/azanella/clang] support: Use CHAR_MAX as maximum value

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=d5bb58332ba2063f09800797906ce9062d2eda00

commit d5bb58332ba2063f09800797906ce9062d2eda00
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue Mar 15 18:01:57 2022 -0300

    support: Use CHAR_MAX as maximum value

Diff:
---
 support/support_process_state.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/support/support_process_state.c b/support/support_process_state.c
index ca86dc11e6..ab02ce9ee1 100644
--- a/support/support_process_state.c
+++ b/support/support_process_state.c
@@ -59,7 +59,7 @@ support_process_state_wait (pid_t pid, enum support_process_state state)
 
   for (;;)
     {
-      char cur_state = -1;
+      char cur_state = CHAR_MAX;
       while (xgetline (&line, &linesiz, fstatus) > 0)
 	if (strncmp (line, "State:", strlen ("State:")) == 0)
 	  {
@@ -67,7 +67,7 @@ support_process_state_wait (pid_t pid, enum support_process_state state)
 	    break;
 	  }
       /* Fallback to nanosleep for invalid state.  */
-      if (cur_state == -1)
+      if (cur_state == CHAR_MAX)
 	break;
 
       for (size_t i = 0; i < array_length (process_states); ++i)