Revert increase of test buffer size.

Signed-off-by: Ryan Everett <ryan.everett@arm.com>
diff --git a/tests/suites/host_test.function b/tests/suites/host_test.function
index 95d30f8..06f391f 100644
--- a/tests/suites/host_test.function
+++ b/tests/suites/host_test.function
@@ -459,7 +459,7 @@
     int ret;
     unsigned total_errors = 0, total_tests = 0, total_skipped = 0;
     FILE *file;
-    char buf[10000];
+    char buf[5000];
     char *params[50];
     /* Store for processed integer params. */
     mbedtls_test_argument_t int_params[50];