some fixes for QSPI flasher script

zedboard-qspi-flasher/qspi-flasher.tcl

@@ -37,7 +37,7 @@ foreach arg $argv {
   if {!$endopts && [string match "-*" $arg]} {
     if {$arg eq "--"} { set endopts 1; continue }
     if {$arg eq "-h" || $arg eq "--help"} { usage; exit 0 }
-    if {$arg eq "-b" || $arg eq "--bin"} { set expecting app; continue }
+    if {$arg eq "-b" || $arg eq "--bin"} { set expecting bin; continue }
     puts "error: unknown option: $arg"; usage; exit 1
   }
 
@@ -84,7 +84,7 @@ if {$bin ne ""} {
 }
 
 if {$bin eq ""} {
-  puts "error: boot.bin binary required as BOOTBIN environment"
+  puts "error: boot.bin binary required"
   usage
   exit 1
 }