cid#1509232 silence Out-of-bounds access

Change-Id: I53f0e0ead728c718d1241d1791135c3c60311303
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/139608
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Jenkins
diff --git a/sal/osl/unx/security.cxx b/sal/osl/unx/security.cxx
index 1b1f16a..b15ec9e 100644
--- a/sal/osl/unx/security.cxx
+++ b/sal/osl/unx/security.cxx
@@ -106,6 +106,8 @@ static oslSecurityImpl * growSecurityImpl(
        }
        p = static_cast<oslSecurityImpl *>(realloc(impl, n));
        if (p != nullptr) {
            // coverity[overrun-buffer-arg] - theoretically massive n is not due to
            // a negative parameter being interpreted as unsigned
            memset (p, 0, n);
        }
    }