trace: simple: pass trace_file unmodified to config-host.h

Add the suffix directly in trace/simple.c, so that quoting is done
properly by Meson.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20211007130829.632254-3-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -4580,8 +4580,6 @@ if have_backend "nop"; then
 fi
 if have_backend "simple"; then
   echo "CONFIG_TRACE_SIMPLE=y" >> $config_host_mak
-  # Set the appropriate trace file.
-  trace_file="\"$trace_file-\" FMT_pid"
 fi
 if have_backend "log"; then
   echo "CONFIG_TRACE_LOG=y" >> $config_host_mak

meson.build

@@ -1571,7 +1571,7 @@ config_host_data.set('HAVE_BROKEN_SIZE_MAX', not cc.compiles('''
 
 ignored = ['CONFIG_QEMU_INTERP_PREFIX'] # actually per-target
 arrays = ['CONFIG_BDRV_RW_WHITELIST', 'CONFIG_BDRV_RO_WHITELIST']
-strings = ['HOST_DSOSUF', 'CONFIG_IASL']
+strings = ['HOST_DSOSUF', 'CONFIG_IASL', 'CONFIG_TRACE_FILE']
 foreach k, v: config_host
   if ignored.contains(k)
     # do nothing

trace/simple.c

@@ -364,7 +364,7 @@ void st_set_trace_file(const char *file)
 
     if (!file) {
         /* Type cast needed for Windows where getpid() returns an int. */
-        trace_file_name = g_strdup_printf(CONFIG_TRACE_FILE, (pid_t)getpid());
+        trace_file_name = g_strdup_printf(CONFIG_TRACE_FILE "-" FMT_pid, (pid_t)getpid());
     } else {
         trace_file_name = g_strdup_printf("%s", file);
     }