kernel32: Fix an off-by-one error in build_envp().

[Francois Gouget]

We need to take into account the trailing NULL in envp.
---

This caused $PATH to be unset in child processes!

 dlls/kernel32/process.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/dlls/kernel32/process.c b/dlls/kernel32/process.c
index 43a1ba2..31d7328 100644
--- a/dlls/kernel32/process.c
+++ b/dlls/kernel32/process.c
@@ -1185,7 +1185,7 @@ static char **build_envp( const WCHAR *envW )
     const WCHAR *end;
     char **envp;
     char *env, *p;
-    int count = 0, length;
+    int count = 1, length;
     unsigned int i;
 
     for (end = envW; *end; count++) end += strlenW(end) + 1;
-- 
1.5.6.5