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>
diff --git a/board/ppmc8260/ppmc8260.c b/board/ppmc8260/ppmc8260.c
index 1808abd..bf0188c 100644
--- a/board/ppmc8260/ppmc8260.c
+++ b/board/ppmc8260/ppmc8260.c
@@ -285,7 +285,7 @@
 	int res;
 
 	if ((ds != 0) && (ds != 0xff)) {
-		res = getenv_r ("ethaddr", (char *)tmp, sizeof (tmp));
+		res = getenv_f("ethaddr", (char *)tmp, sizeof (tmp));
 		if (res > 0) {
 			ss = ((ds >> 4) & 0x0f);
 			ss += ss < 0x0a ? '0' : ('a' - 10);