Rename getenv_r() into getenv_f()

While running from flash, i. e. before relocation, we have only a
limited C runtime environment without writable data segment. In this
phase, some configurations (for example with environment in EEPROM)
must not use the normal getenv(), but a special function.  This
function had been called getenv_r(), with the idea that the "_r"
suffix would mean the same as in the _r_eentrant versions of some of
the C library functions (for example getdate vs. getdate_r, getgrent
vs. getgrent_r, etc.).

Unfortunately this was a misleading name, as in U-Boot the "_r"
generally means "running from RAM", i. e. _after_ relocation.

To avoid confusion, rename into getenv_f() [as "running from flash"]

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>

arch/sparc/lib/board.c

@@ -88,7 +88,7 @@ ulong monitor_flash_len;
 static int init_baudrate(void)
 {
 	char tmp[64];		/* long enough for environment variables */
-	int i = getenv_r("baudrate", tmp, sizeof(tmp));
+	int i = getenv_f("baudrate", tmp, sizeof(tmp));
 
 	gd->baudrate = (i > 0)
 	    ? (int)simple_strtoul(tmp, NULL, 10)