sim: eliminate (some) overwrite cfg

Remove some compile-time configuration of the overwrite-only flag.
These will be decided by doing a dynamic query of how the mcuboot code
has been compiled.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/sim/src/image.rs b/sim/src/image.rs
index 0419cbe..a25e738 100644
--- a/sim/src/image.rs
+++ b/sim/src/image.rs
@@ -38,13 +38,11 @@
         }
     }
 
-    #[cfg(feature = "overwrite-only")]
     pub fn run_basic_revert(&self) -> bool {
-        false
-    }
+        if Caps::OverwriteUpgrade.present() {
+            return false;
+        }
 
-    #[cfg(not(feature = "overwrite-only"))]
-    pub fn run_basic_revert(&self) -> bool {
         let mut fails = 0;
 
         // FIXME: this test would also pass if no swap is ever performed???
@@ -145,13 +143,11 @@
         fails > 0
     }
 
-    #[cfg(feature = "overwrite-only")]
     pub fn run_revert_with_fails(&self) -> bool {
-        false
-    }
+        if Caps::OverwriteUpgrade.present() {
+            return false;
+        }
 
-    #[cfg(not(feature = "overwrite-only"))]
-    pub fn run_revert_with_fails(&self) -> bool {
         let mut fails = 0;
 
         if Caps::SwapUpgrade.present() {
@@ -167,13 +163,11 @@
         fails > 0
     }
 
-    #[cfg(feature = "overwrite-only")]
     pub fn run_norevert(&self) -> bool {
-        false
-    }
+        if Caps::OverwriteUpgrade.present() {
+            return false;
+        }
 
-    #[cfg(not(feature = "overwrite-only"))]
-    pub fn run_norevert(&self) -> bool {
         let mut flashmap = self.flashmap.clone();
         let mut fails = 0;
 
@@ -532,7 +526,6 @@
     (flashmap, count - counter)
 }
 
-#[cfg(not(feature = "overwrite-only"))]
 fn try_revert(flashmap: &SimFlashMap, areadesc: &AreaDesc, count: usize) -> SimFlashMap {
     let mut flashmap = flashmap.clone();
 
@@ -544,7 +537,6 @@
     flashmap
 }
 
-#[cfg(not(feature = "overwrite-only"))]
 fn try_revert_with_fail_at(flashmap: &SimFlashMap, images: &Images,
                            stop: i32) -> bool {
     let mut flashmap = flashmap.clone();